Skin loses its tone and smooth texture as it ages, commonly developing wrinkles and laxity. This can be further compounded by photodamage and other effects such as, e.g., scarring from acne or trauma, age-related rhytides, and striae. Aged skin is characterized by a flattened dermal-epidermal junction, thinning epidermis and dermis, less fibrous collagen, and alterations in elastin organization. Skin rejuvenation therapies can work to remove these damaged tissues and/or and stimulate the growth of new, healthy collagen, elastic fibers and skin cells and thereby improve the appearance of the skin.
A common procedure for skin rejuvenation, laser resurfacing, uses light energy to heat and damage the upper dermis. However, laser resurfacing has a poor side effect profile, with many patients experiencing prolonged erythema, scarring and dyspigmentation. Recently, the development and use of fractional ablative therapy has achieved better results. A fractional damage can include forming small regions of damage in tissue (e.g., ablation or thermal damage) that are surrounded by healthy tissue. A small size of the damaged regions (e.g., generally less than about 1 mm) and proximity of healthy tissue can facilitate a rapid healing of the damaged regions, as well as other desirable effects such as tissue shrinkage.
Laser-based fractional resurfacing techniques and devices involve the use of expensive and potentially dangerous lasers or other sources of intense optical energy to damaged tissue. Such optical systems can be expensive, present safety hazards, and require a skilled physician or clinician for their operation.
Percutaneous collagen induction therapy (PCI), another approach for mechanically inducing cosmetic improvements in skin tissue, is based on the use of stamps or rollers to insert small solid needles through the epidermis and into the dermis of the skin to stimulate collagen growth. This technique can improve the appearance, e.g., of acne, burn scars and striae without removal of tissue, and may provide an improved side effect profile, but generally has exhibited limited clinical efficacy. Because PCI does not heat the skin, needling devices also avoid the erythema and scaring that may be associated with laser treatment, and have significantly less recovery time.
Accordingly, there may be a need for a relatively simple, inexpensive, and safe cosmetic method and device that can be mechanical in nature and would overcome at least some of such exemplary deficiencies, and can be configured to produce fractional damage in biological tissue that is well-tolerated.